Sight for firearm



Dec. 13,1960

G. WILHELM SIGHT FOR FIREARM Filed Jan. 50. 1959 SEAR-8% WWW INVENTOR GARY W/LHELM WWMM 61's Arro msys'.

United States Patent SIGHT FOR FIREARM Gary Wilhelm, New Haven, 'Conn., assignor to The High Standard Manufacturing Corporation, Hamden, C0nn., a corporation of Connecticut Filed Jan. 30, 1959, Ser. No. 790,285

Claims. (Cl. 33-56) This invention relates to sights for firearms, and it relates more particularly to rear sights which are adjustable for windage and elevation.

Due to the fact that gun sights are necessarily compact in size, adjustable sights are in most instances of rather delicate construction and are easily damaged. Moreover, because of its compactness and the size of the parts employed, it is difficult to provide distinctly audible click-adjustments for the windage and elevation screws, due to space limitations which normally preclude the use of heavy enough spring detents. In addition, sights that are accurately adjustable for both windage and elevation are usually comparatively expensive to manufacture and are not conducive to production on a large scale.

It is, therefore, an object of the present invention to provide a sight that is simple in construction and, therefore, is easy to manufacture, while at the same time provides an accurate and true sight picture in shooting. Another object of the invention is to provide an adjustable sight which is of rugged construction, but which is still compact. A further object is to provide windage and elevation adjusting screws having sharp step-by-step adjustment characterized by distinctly audible clicks between each increment of adjustment.

With the above objects in view, as well as others which will be apparent to those skilled in the art from the description hereinafter, a gun sight embodying the invention comprises a sight leaf hinged to a fixed base and resiliently urged upwardly in elevational movement with respect to said base, a cross-member arranged for pivotal engagement with said base, and an elevation adjusting screw threaded to said cross-member for limiting the upward movement of said leaf. As the leaf is adjusted upwardly by turning the elevation screw in one direction, the cross-member pivots slightly in order to compensate for the change in the angular relationship between the elevation screw and the base of the sight. In addition, since it is desirable for several reasons that the elevation screw be disposed at a fixed anglepreferably perpendicular-to the leaf regardless of the position to which it is adjusted, the cross-member is supported on the base in such a way that it can move slightly longitudinally of the base, in order to prevent the elevation screw from binding in the cross-member or tilting with respect to the leaf. The cross-member is likewise permitted to move transversely of the base so that the leaf, together with the elevation screw can be moved transversely of the base for windage without in any way interfering with or affecting the elevation.

A rear sight embodying the invention in its most advantageous form is illustrated in the accompanying drawings, in which Fig. 1 is a side elevational view of a rear sight with a portion of the firearm on which it is mounted shown in broken lines;

'Fig. 2 is a top plan view of the sight;

Fig. 3 is a bottom plan view thereof;

Fig. 4 is a front end view thereof;

2,963,789 Patented Dec. 13, 1960 ice Fig. 5 is a longitudinal section taken on the line 5-5 in Fig. 2;

Fig. 6 is a transverse section taken on the line 6-6 in Fig. 1; and

Fig. 7 is a diagram illustrating the relative movement of the parts.

The primary components of the sight illustrated in the drawings are the base 10 with a sight leaf 12 hinged thereto adjacent its forward edge, an elevation adjustment screw 14 for raising and lowering leaf 12 and a windage adjustment screw 16 for moving leaf 12 transversely with respect to base 10. Base 10 may be fixed on the upper side of the barrel or other part of a firearm 18 in any conventional manner, as for example by means of the dovetail portion 20 in the underside of base 10, which fits in a corresponding transverse groove in the gun. Aligned holes 22 and 23 are provided in the leaf 12 and base 10, respectively, in order to permit a set screw (not shown) or other suitable locking means, such as a roll pin, to be driven into engagement with the bottom of the groove in the gun 18, thereby rigidly preventing transverse movement of the base 10. Extending forwardly of and integral with dovetail portion 20 of base 10, are side walls 24 and 26 supporting a shaft 28, to which leaf 12 is pivoted.

Sight leaf 12 is provided with a wide rectangular rear flange 29 disposed approximately perpendicular to the line of sight, with its lower edge almost engaging the upper surface of the firearm when leaf 12 is in its lowest position, as shown in Fig. 1. The upper edge of flange 29 is disposed somewhat above the upper surface of leaf 12 and has a sighting notch 29 formed centrally between its lateral extremities.

On the underside of sight leaf 12 adjacent its forward edge is an integrally formed bearing block 30, which extends downwardly between side walls 24 and 26 of base 10 and, as may be seen in Fig. 3, is substantially narrower laterally of the sight than the space between the inner surfaces of said side walls. Shaft 28 extends through a bearing passage provided in bearing block 30 so that leaf 12 may be pivoted upwardly from the position shown in the drawings. In addition, due to the fact that bearing block 30 is narrower than the space between side walls 24 and 26 of base 10, leaf 12 may be moved transversely of base 10 on pivot shaft 28. Bearing block 30 is provided adjacent one side with a rearwardly extending lug 32, into which windage adjustment screw 16 is threaded. A large flat head 34 on the opposite end of windage screw 16 bears against the outer side of side wall 24 of base 10. Screw 16 fits freely through an aperture 36 in side wall 24, aperture 36 being elongated slightly vertically, as shown in Fig. 5, in order to permit screw 16 to move upwardly when leaf 12 is elevated. A coil spring 38, which surrounds the shank of screw 16, is compressed between lug 32 on sight leaf 12 and the inner side of side wall 24, and continuously urges leaf 12 to one side of base 10.

It will be apparent from the foregoing that by turning screw 16 so that lug 32 is drawn against spring 38, the sight leaf is moved to the left, as viewed in Fig. 4, while turning screw 16 in the opposite direction permits leaf 12 to be moved by spring 38 in the other direction transversely of base 10.

In order to prevent accidental rotation of screw 16, which would change the windage adjustment of the sight, a spring-loaded detent plunger 40 is provided in an axial bore drilled in the end of pivot shaft 28 adjacent to the head 34 of screw 16. The outer end of detent plunger 40 engages the inner side of head 34 of screw 16 adjacent its periphery, where a plurality of spaced recesses 42 are formed in order to receive detent plunger 40 and thereby restrain rotation of screw 16 at any selected 3 position. The opposite end of pivot shaft 28 is provided with a shoulder 44 (Fig. 3) formed by a reduced diameter end portion 46 which is supported in the side wall 26 of base 10. Shaft 28 is therefore prevented from moving axially in one direction by the engagement of shoulder 44 with side wall 26, and in the other direction by the head 34 of screw 16 against which detent 40 presses.

Referring now more particularly to Figs. and 6 and the manner in which sight leaf 12 is adjusted for elevation, the shank of elevation adjustment screw 14 passes freely through an aperture 50 in leaf 12 located forwardly of flange 29. A circular recess 52 is provided in the upper surface of leaf 12, in order to receive a large flat head 54 on screw 14 similar to that of windage adjustment screw 16. The bottom of recess 52 lies within or parallel to the plane of leaf 12. Since, as will become more apparent hereinafter, the inner surface of head 54 of screw 14 is held in intimate engagement with the bottom of recess 52, the shank of screw 14 will at all times extend perpendicularly to leaf 12.

A cylindrical cross-member 56 is supported on base in enlarged holes 58 provided in side walls 24, 26, thereof. A threaded bore 60 extending transversely through the mid-section of cross-member 56 receives the threaded end of elevation screw 14, while a pair of transverse passages 62 and 64 extend parallel to and on either side of screw 14. Guided within each of said passages 62 and 64 are lifting springs 66 and 68, respectively, which bear downwardly on frictionless bearing means shown as balls 70, 72, which project slightly below the bottom of said passages into engagement with base 10. Said lifting springs 66, 68 press upwardly against the underside of leaf 12 in order to urge said leaf upwardly against the head 54 of elevation screw 14. Holes 74 and 76 in the bottom of recess 52 in leaf 12 are provided on either side of aperture 50 in order to position the upper ends of a pair of plungers 78 and 80, respectively, which fit within lifting springs 66 and 68. Each of plungers 78, 80 is formed with a flange 82 that engages the underside of leaf 12 so as to normally transmit to it the force exerted by lifting springs 66, 68.

Plunger 80 has an upwardly extending detent nose 84 which projects above the bottom of recess 52 into detent recesses 86 on the underside of head 54. Rotation of elevation screw 14 causes plunger 80 to be moved downwardly against its spring 68 and then to snap back into the next recess 86. Plunger 80, therefore, performs the dual function of helping to lift leaf 12 in its elevational movement and at the same time of acting as a detent to prevent accidental rotation of elevation screw 14. The detent recesses 86 are arranged in the same manner as those provided on windage screw 16, where in this instance there are provided ten such recesses on each of the adjustment screws in order to provide ten distinct settings for each revolution of the screw. Because of the particular arrangement of parts, the detent plungers and springs may be comparatively large with the result that the detents for each of the adjustment screws make clearly audible and distinct clicks as the screws are rotated. The upper end of the plunger 78 on the other lifting spring 66 projects only partially into its hole 74 and therefore does not engage the underside of elevation screw 14. The balls 70, 72 in the bottom of passages 62, 64 of cross-member 56 ride against the bottom of a groove 88 formed co-extensively with supporting holes 58 in base 10 in which cross-member 56 is located. The upper front corners 90 of side walls 24, 26 of base 10 are bevelled off as shown in Fig. 1 in order to permit leaf 12 to tilt upwardly to the desired limit of elevational movement of said leaf. If desired, bevelled corner 90 may be formed so as to restrict the total movement of leaf 12 in elevation in order to permit complete removal of elevation screw 14 without releasing lifting springs 66, 68 and bearing balls 70, 72.

'It will be appreciated from the foregoing that crossmember 56 can move transversely of base 10 when the leaf 12 is adjusted for windage and that such adjustment has no effect on the lifting springs 66 and 68 or on the elevation adjustment screw 14. Balls 70 and 72 reduce the resistance to such movement caused by the pressure exerted by springs 66 and 68 against base 10. Provision of balls 70 and 72 in this connection is important, because if there were too much friction between leaf 12 and base 10, spring 38 might not move leaf 12 transversely of base 10 when windage adjustment screw 16 is backed olf from the lug 32.

As is apparent from Figs. 1 and 5, the diameter of holes 58 in the side walls 24 and 26 i and of groove 88 of base 10 is substantially larger than the diameter of cross-member 56 thereby permitting cross-member 56 to move laterally of itself, or longitudinally with respect to base 10, as well as transversely thereof. Such longitudinal movement of the cross-member relative to base 10 is essential where, as in the specific embodiment of the invention illustrated in the drawings, it is necessary to maintain the elevation screw 14 perpendicular to or at least at some fixed angle to the leaf 12. This will be more readily apparent by reference to the diagram of Fig. 7. The points a, b and 0 represent points on leaf 12, a being the pivot point of leaf 12 on base 10, b a point in the plane of leaf 12 directly above the pivot a, and c the point at which elevation screw 14 intersects the plane of the sight leaf (see Fig. 5). The line he in Figs. 5 and 7, therefore, may be considered as representing the plane of the leaf. In the solid line showing in the diagram of Fig. 7, as well as in the various other views in the drawings, the leaf is in its down position and plane be is substantially parallel with the plane bx of the base 10, x being the point at which the elevation screw 14 intersects the base plane when the leaf is not elevated.

When the elevation screw 14 is rotated so as to elevate leaf 12 to the broken line position shown in Fig. 7, the plane of leaf 12 is tilted to the position b'c. Since the flat head 54 of screw 14 remains flush with leaf 12, screw 14 continues to extend perpendicularly to leaf 12 (plane b'c') and screw 14 therefore tilts an equal amount so that it intersects the plane of base 10 at x somewhat to the right (as shown in Fig. 7) of the original point of intersection x. Consequently, cross-member 56, to which screw 14 is threaded, must move to one side as the sight is adjusted for elevation. In addition it pivots in order to compensate for the amount which screw 14 tilts. Such compound movement of cross-member 56 is permitted by the enlarged holes 58 in which cross-member 56 is mounted.

Due to the arrangement in which the lifting springs 66, 68 press upwardly against leaf 12 while screw 14 limits such upward movement, cross-member 56 will always engage the upper sides of holes 58. It will be apparent, therefore, that the surface against which cross-member 56 rides could be flat instead of curved as specifically illustrated. In fact, a flat surface parallel to the plane of base 10 would theoretically provide more accurate adjustment of the sight in elevation. However, since the amount of lateral movement of cross-member 56 is comparatively small in the present instance, the error introduced by the curvature of hole 58 is so slight that it can be disregarded. In the present construction, moreover, it has been found desirable for ease of manufacture to form the enlarged circular holes 58. However, since only the upper sides of holes 58 are engaged by cross-member 56 the lower portion of base 10 could be cut away entirely' if, for example, it were desired to provide the mounting dovetail 20 of base 10 at some other point. This would leave the lower half of cross-member 56 exposed and would, therefore, require some other means for supporting lifting springs, which could be rather easily arranged.

What is claimed is:

1. In a sight for firearms, the combination comprising a fixed base, a sight leaf hingedly mounted on said base for elevational movement with respect thereto, a windage adjustment screw for adjusting said leaf transversely of said base, a cross-member pivotally engaging said base and having a longitudinal axis disposed transversely thereof, a spring extending between said base and said leaf to urge said leaf upwardly in its elevational movement, said spring being guided in a passage in said cross-member, an elevation adjustment screw having an enlarged head portion in engagement with the upper side of said leaf at a fixed angle and limiting the upward movement thereof, said elevation adjustment screw being threadedly connected to said cross-member so that the cross-member is movable transversely of the base along with the leaf and adjustment screw, the enlarged head portion of said screw having a plurality of recesses annularly disposed in the underside thereof, said cross-member being movable longitudinally of the base to allow elevational movement of the leaf and the elevation adjustment screw at said fixed angle with respect to each other, and a detent plunger extending through said leaf into resilient engagement with the recesses in the underside of the enlarged head portion of said elevation adjustment screw in order to provide step-by-step adjustment thereof.

2. The combination defined in claim 1, which includes a second spring guided in another passage on the opposite side of said threaded bore and parallel thereto, said second spring acting upwardly against the underside of said leaf in order to continuously urge said leaf against said head portion of said elevation screw.

3. In a sight for firearms, the combination comprising a fixed base, a sight leaf hingedlymounted on said base for elevational movement with respect thereto, a windage adjustment screw for adjusting said leaf transversely of said base, an elongated generally cylindrically shaped cross-member pivotally engaging said base and having a longitudinal axis disposed transversely thereof, a coil spring extending between said base and said leaf to urge said leaf upwardly in its elevational movement, said spring being guided in a transverse passage in said elongated cross-member, an elevation adjustment screw having an enlarged head portion in engagement with the upper side of said leaf at a fixed angle and limiting the upward movement thereof, said elevation adjusting screw being threadedly connected to said cross-member in a threaded bore substantially midway between its ends and parallel to said transverse passage therein so that the cross-member is transversely movable of the base along with the leaf and adjustment screw, the enlarged head portion of said elevation adjustment screw having a plurality of recesses annularly'disposed in the underside thereof, said cross-member also being movable longitudinally of the base to allow elevational movement of the leaf and the elevation adjustment screw at said fixed angle with respect to each other, and a detent plunger extending through said leaf into resilient engagement with the recesses in the underside of the enlarged head portion of the elevation adjustment screw in order to provide stepby-step adjustment thereof.

4. In a sight for firearms, the combination comprising a fixed base, a sight leaf hingedly mounted on said base for elevational movement with respect thereto, a windage adjustment screw for adjusting said leaf transversely of said base, a cross-member pivotally engaging said base and movable with said leaf transversely of said base, spring means urging said leaf upwardly in its elevational movement, an elevation adjustment screw threadedly connected to said cross-member, said elevation adjustment screw having a portion engaging said leaf and limiting the upward movement thereof; said sight leaf being hinged to said base by means of a pivot shaft disposed transversely of said base and said windage adjustment screw being disposed parallel and adjacent to said shaft, said windage adjustment screw having an enlarged head portion in engagement with a portion of said base and extending across one end of said pivot shaft, said head portion having a plurality of recesses disposed annularly on its inner side, and a spring-loaded detent plunger provided axially within said end of said pivot shaft extending into resilient engagement with said recessed inner surface of said enlarged head portion in order to provide step-by-step adjustment of said windage screw.

5. In a sight for firearms, the combination comprising a fixed base, a sight leaf hingedly mounted on said base for elevational movement with respect thereto, spring means constantly urging said sight leaf in one direction transversely of said base, a windage adjustment screw for adjusting said leaf transversely of said base against the urging of said spring means, a cross-member pivotally engaging said base and movable transversely thereof, an elevation adjustment screw having a portion engaging said leaf so as to be movable therewith transversely of said base, said elevation adjustment screw being threadedly connected to said cross-member and limited in its upward movement thereby, spring means between said leaf and said base urging said leaf upwardly in its elevational movement, and frictionless bearing means for said spring means to facilitate movement of said spring means transversely of the base with the leaf, cross-member and elevation adjustment screw.

References Cited in the file of this patent UNITED STATES PATENTS 2,112,268 Burton Mar. 29, 1938 2,438,601 Davis Mar. 30, 1948 2,854,748 Williams Oct. 7, 1958 

